Retractable cord reels have been used in various applications to retractably store various types of cables. The cable held on the reel typically has a stationary end portion and a portion that may be extended from and retracted back into the reel. Conventionally, the reel comprises a spring-loaded spool on which the extendable portion of cable is wound. The extendable portion of the cable may be withdrawn from the reel, causing the spool to rotate against the force of the spring. Upon release of the cable, the spring causes the spool to rotate in the opposite direction thereby retracting the cable back onto the spool. A problem common to all prior art cord reels is providing a continuous electrical and data connection between the rotating extendable portion of the cable and the stationary end portion. Two basic types of cord reels have been developed to address this problem.
One type of reel utilizes rotating contacts, commonly placed between the rotating reel and a stationary housing. The stationary end portion of the cable is separate from the extendable portion. The stationary cable is connected to the contacts carried by the housing, and the extendable portion is connected to the contacts carried by the reel. When the reel rotates, substantially continuous contact is made between the rotating contacts. However there are numerous, well documented disadvantages of cord reels having moving contacts. Moving contacts have a propensity to spark, making such reels unsuitable for use in wet environments, hazardous environments and in medical applications, among others.
To overcome these problems, a second type of retractable cord reel has been developed that eliminates contacts. The reel comprises a spool on which the extendable portion of cord is held, an expansion chamber in which a fixed length of cable is spirally wound. The two cable portions are connected, typically in or adjacent the hub of the spool. As the spool rotates the spirally wound, fixed cable expands and contracts within the expansion chamber. An example of reels of this type is disclosed in U.S. Pat. No. 5,094,396 to Burke, the disclosures of which are hereby incorporated by reference.
Regardless of the success of this second kind of cord reel, it would be advantageous to have a cord reel assembly without any need for connections, which can be the subject of defects in soldering, potting chambers or similar connection points. In order to ensure a more durable and more reliable system for connecting to and supporting electronics connected to cord reels, it is necessary to provide a cord configuration to enable the connection of a continuous cord to such devices.
To date, however, there are no available products that permit a continuous cord to provide a cord reel with retractable and stationary ends.
What is needed is a cord reel assembly having retractable and stationary ends which employ a single, continuous cord so as to eliminate electrical and/or mechanical interconnection points in connecting to electronic devices.